It is proposed to complete the currently undergoing studies on the amino acid sequence of the 'sigma' and 'beta' subunits of human pituitary FSH. The amino acid and carbohydrate sequence of biologically active fragments of FSH and LH isolated by controlled enzymatic degradation will also be undertaken. Similar studies will be performed on FSH being isolated from horse pituitary glands. Products of enzymatic and chemical degradation of proteins and carbohydrate moieties are isolated by gel filtration, chromatography and high-voltage electrophoresis. The amino acid sequences of the peptides are established by stepwise degradation by the Edman's procedure, carboxypeptidase A and B digestion. The identification of amino acid is performed by amino acid analysis or by gas liquid chromatography. The elucidation of the primary structure of FSH will aid in the eventual chemical synthesis of the hormone. Receptor for FSH, LH and HCG and prolactin will be indentified and characterized in the ovaries of rat, cow and human at various stages of the reproductive cycle. Using detergents, gel-filtration and affinity chromatography, we propose to isolate gonadotropin receptor from the ovaries. The purified receptor will be characterized in terms of hormone binding, and antigenicity as well as lipid, carbohydrate and amino acid compositions. Hormone-specific antibodies against FSH, LH, TSH and HCG and their subunits will be raised in rabbits and guinea pigs and isolated by rivanol precipitation, immunoabsorption and affinity chromatography. The pure hormones, receptors and radioimmuno and radioreceptor assays will be used in developing in vitro models to study biochemical mechanism of hormone action.